Remove for ease of leaning into the engine bay. I actually spent half my time sitting/squatting/standing inside the trunk space. I had removed all of the panels and carpeting to change the air filter, so I left them out until I was done.

Side note: I accessed the plug wires and "manifold bolt removal" from underneath and sliced up my forearms on the subframe. Quick deburring with a file solved that issue.

 

Soul apparently uses the same 6 inch German made cores that Fabspeed does. Fabspeed claims a 6 HP improvement which is in line with other cat manufacturers. Does this mean Soul is different (not likely), however, it does mean that the dyno they used indicated a higher improvement reading than all the others. Remember the Motor Trend dyno of a C8 indicating massive HP in the 600+ range? Happy Motoring…

 

I did the ARH headers with studs, was about a 3 hour job. Don’t know what issues you had, but the back bumper definitely does no need to come off. Not much you actually need coming from the back. The only time i had to get under the car was for removal of the wires with the stock manifolds on. Once the headers went on everything was done from the top.

 

Did you install the studs before you installed the headers? Or after? I attempted to install before, realized they wouldn't fit with the studs pre-installed. Once I had to uninstall the studs, I figured it was just easier to use the provided hardware, versus the extra steps of stud install, then nut.

The ARP studs I bought will be used on another of my cars, so not wasted.

 

Before. Just had to angle the headers.

 

Disconnect the evap line on the passenger side and there is plenty of room. All the header bolts were torqued from the top.

 

Does anyone have any dynos that show 30+ rwhp gains for ARH headers other than from ARH themselves? I found one company that showed a 33hp gain but I feel like if this were actually true there would be way more evidence of it around to find.

 

I'd like to see more results as well. I'd really like to see ARH headers plus a ported TB. if it is a good combo, I'd be all over it.

 

JTM Sports (third party Dyno test results for C8 with ARH headers).

 

Although I am not shlepping for ARH, I did install the headers on my Z51 C8 HTC and found them to be not only sounding better, but seat of the pants improvement throughout the entire range. I have not had the opportunity to dyno the improvements which include a new air filter, Magnaflow Xmod exhaust system,and Soler throttle body, but. can feel the difference. Side by side with a stock C8 reveals a complete walk away. Other manufacturers may have similar or even better results, but we all know, that since 1955, the Chevy small block, notwithstanding cubic inches, is a motor that thrives on exhaust and intake airflow improvements. Happy Motoring!!!

 

That's impressive. +30HP at some RPM and almost +40TQs at some RPM. Eagerly awaiting the halltech intake. Seriously considering the Harding pTR with Lingenfelter 95mm TB, too.

 

I don't trust this completely. This is the same dyno graph published on ARH's website. I want to see dyno sheets of other people, not just the one single one that ARH has on their own website.

 

Get a set and do a Dyno

 

I will... once I see definitive proof that they pick up 30rwhp from independent proven testing and not just "because ARH says they do with one dyno graph." I feel like if it did pick up that much it would be way easier to find different people who have done it either on forums or youtube. LMR did a test and showed they only gained 11 rwhp with the headers. 13:08 is the dyno graph: - Their results were:

Stock - 439.01 rwhp / 414.79 tq
LMR Cats/catback - 461.89 rwhp / 444.79 tq (difference of +22.88 rwhp from stock)
LMR Cats/catback/ARH headers - 473.06 rwhp / 458.36 tq (difference of +11.17 rwhp from just cats/catback)

So in this test, they gained more by using aftermarket cats and catback than they did with headers. The stock manifold in the c8 is already pretty well designed as it is... I really don't see 30rwhp being possible from headers alone, and the lack of evidence from independent testers to show 30rwhp gains when there have been multiple headers produced from different companies over the last year of the car being out supports my theory. I'm not dropping $2,000+ to be one company's guinea pig and not being able to return the product if it doesn't end up netting the gains claimed, which according to LMR's testing, won't even come close to their claims.

 

So don’t get a set, who cares. Lol

 

Well then, you will need to either bite the bullet and install the headers or sit on the sidelines and watch. I can say with conviction, that the ARH long tube headers (vs. OEM short tube which is the big difference) headers, a Magnaflow X Mod cat back exhaust system, a Soler throttle body and replacement air cleaner on my Z51 C8 literally walks away from a stock C8 Z51…embarrassingly so. But don’t take my word for it…do some research such as TJ Hunt’s dig with his similarly equipped C8 vs a stocker. Do the ARH enjoy claimed hp increases, I don’t know, but they sure help my C8 to blow past a stocker. Cheers!

 

LMR seem to be promoting their product only. I just can't see why some members praise dyno numbers most of the time. I have seen the difference between these aftermarket market exhaust system and cats.....didn't do almost nothing as far as performance on the track. The two quickest C8 have ARH headers, one with aftermarket exhaust and one without. They are running basically the same times at the drag strip....10.50's. American Racing even admitted that their catback eventually received hardly no gains on the dyno....so it's a waste as far as I am concerned. To this day American Racing is the only proven headers at the track.

 

I haven’t seen any other ARH C8 dynos other than the one I posted, however, just because it is the only one so far doesn’t make it fraudulent. ARH has been in the header business for decades and enjoys a top rate reputation for increasing HP via their long tube headers. It would be great if you bought a set and dyno’d. the results. Think of it as magnanimous act for the entire C8 community…. Happy Motoring!

 

Why not contact ARH for further tests/details and let us all know. Maybe they can convince you that their headers do the trick…Cheers.

 

I'm not going to go hunt it down, but my recollection is other dynos have shown peak HP gains are closer to 15 to 20, but gains in torque, especially below peak torque can be in the 30 TQ range or more. For the last 2 decades, quality headers for GM V8s have consistently produced nice mid range gains along with some acceptable peak HP gains.

Should I keep my C8, a set of ARH headers will be going on them.